KR102381256B1 - Manufacturing method of silicon oxide powder for cathode material of secondary battery and secondary battery using the same - Google Patents

Abstract

The present invention relates to a method for manufacturing silicon oxide powder for a secondary battery negative electrode material and a secondary battery using the same.
The method for producing silicon oxide powder for a secondary battery negative electrode material of the present invention is to wet-react silicon chloride as a first reactant material and polyhydric alcohol or water as a second reactant material to produce silicon oxide in a gel state, Accurately control the conditions of the input sequence of the first reactant and the second reactant, the input rate, and the mixing ratio of the reactant to achieve physical properties suitable for secondary battery negative material use, and use ultrasonic stirring for the silicon oxide in the gel state By dispersing the particles, the particle size is small and the particle size distribution is uniform, the repetitive sintering and pulverization steps can be omitted in the process, and the reversible capacity and reversible ratio are improved using the obtained silicon oxide powder for secondary battery negative materials. A secondary battery may be provided.

Description

Manufacturing method of silicon oxide powder for secondary battery negative electrode material and secondary battery using same

The present invention relates to a method for manufacturing silicon oxide powder for a secondary battery negative electrode material and a secondary battery using the same, and more particularly, to a gel by wet reaction of silicon chloride as a first reactant material and polyhydric alcohol or water as a second reactant material. To produce silicon oxide in a state of being, achieve physical properties suitable for secondary battery negative material use by precisely controlling the order, input rate, and mixing ratio of the reactant to the reaction vessel of the first and second reactants And, by dispersing the silicon oxide in the gel state using ultrasonic agitation, the particle size is small, has a uniform particle size distribution, and a method for producing a silicon oxide powder for a secondary battery negative electrode material that can omit a separate pulverization step and using the same It relates to secondary batteries.

As the need for secondary batteries is highlighted in the miniaturization and high performance of portable devices, electric vehicles and large-capacity energy storage industries, the demand for performance improvement of lithium secondary batteries is increasing.

The lithium secondary battery has a higher operating voltage and energy density than other secondary batteries, and can be used for a long time, so that it can satisfy complex requirements according to the diversification and complexity of devices.

These lithium secondary batteries use repeated insertion and extraction reactions of Li ions, and currently commercially available cathode active materials include LiCoO ₂ , LiNi _0.33 Co _0.33 Mn _0.33 O ₂ , LiMn ₂ O ₄ , and the like. A transition metal oxide is used, and a graphite-based material is widely used as an anode active material.

However, the graphite-based material has a small capacity (theoretical capacity: about 372 mAh/g, about 830 mAh/ml, reversible capacity: about 330 mAh/g), and stability problems occur when charging at a high rate. In addition, due to the non-uniform solid electoyte interface (SEI) occurring after the initial cycle, lithium ions are prevented from diffusing from the electrolyte to the graphite, resulting in significant irreversible loss of capacity, resulting in electrode collapse and cycle instability.

In order to replace the graphite-based material, materials such as Si, Ge, and Sn, which are Group 4 semiconductor materials, are attracting attention as new negative electrode materials because they have high theoretical capacity. The voltage is also known to be the lowest and is receiving the greatest attention.

In particular, silicon oxide (SiOx) is known to be an anode material for a lithium ion secondary battery having a large electric capacity and excellent lifespan characteristics.

As a method of manufacturing the silicon oxide (SiOx) powder for the secondary battery negative electrode material, it is prepared in the form of nanopowder by a dry gas-phase spraying method or a wet liquid-phase manufacturing method.

In general, the dry gas phase spray method is to produce silicon oxide (SiOx) by reacting a small amount of oxygen with metal silicon. Although there are advantages, there are disadvantages in that it is difficult to select the particle size of ultra-fine particles, and repetitive sintering and pulverization processes are required, which increases the manufacturing cost and greatly increases the manufacturing time. In particular, there is a problem in the uniformity of the particle size or the homogeneity of the chemical composition.

On the other hand, the wet liquid manufacturing method is a method of growing silicon oxide (SiOx) crystals by reacting silicon chloride (SiCl ₄ ) and ethylene glycol (EG, Ethylene Glycol). It is small, has a large surface area, has a uniform particle size distribution, and has the advantage of obtaining a homogeneous composition ratio. A method for manufacturing silicon oxide (SiOx) that is stable and has excellent physical properties by further improving crystal growth, crystal grain size uniformity, heat control, and by-product treatment of silicon oxide (SiOx) has not yet been established.

Accordingly, as a result of the present inventors' efforts to solve the problems in the prior art, in the reaction of silicon chloride as the first reactant and polyhydric alcohol or water as the second reactant, the first reactant and the second reactant are placed in a reaction vessel. A silicon oxide powder for a secondary battery negative material with excellent physical properties is manufactured by precisely controlling the conditions of the input sequence, the input speed, and the mixing ratio of the reactants, and a dispersion step by ultrasonic stirring is performed to achieve a uniform particle size distribution of the nanopowder size. By controlling to have and confirming that it is possible to omit the repetitive sintering and grinding steps in the process, the present invention was completed.

Korean Patent No. 1999911 Korean Patent No. 1582385 Korean Patent No. 1463171

It is an object of the present invention to provide a method for producing a silicon oxide (SiOx) powder for a secondary battery negative electrode material.

Another object of the present invention is to provide a secondary battery using silicon oxide (SiOx) powder for a secondary battery negative electrode material as an anode material.

In order to achieve the above object, the present invention provides a wet reaction between silicon chloride as a first reactant material and polyhydric alcohol or water as a second reactant material in a reaction vessel, wherein the volumetric mixing ratio of the first reactant material and the second reactant material is 1 : A reaction step for generating silicon oxide (SiOx) in a gel state by adding less than 1.5; and

A heat treatment step for heat-treating the silicon oxide in the gel state to produce a silicon oxide powder,

In the reaction step, after the entire amount of the first reactant is put into the reaction vessel, the second reactant is added at an administration rate of less than 5 vol%/min and reacted while the second reactant is subsequently added. Provided is a method for producing a silicon oxide powder for an anode material.

In the manufacturing method of the present invention, after the reaction step, a dispersing step using ultrasonic stirring of the generated silicon oxide in a gel state may be further performed.

Specifically, in the reaction step, the volume mixing ratio of the first reactant and the second reactant is preferably 1:0.5 to 1:1.0.

In addition, in the reaction step, it is preferable that the second reactant is introduced at an administration rate of 0.5 vol% to 2 vol%/min.

In this case, it is preferable that an inert gas is supplied into the reaction vessel in the reaction step, and the heat treatment step is performed at a first atmospheric step maintained at 100±20° C., a preheating step maintained at 400±20° C., and 600 to 900° C. The firing step, the second standby step, and the cooling step (S250) are performed.

In this case, by supplying an inert gas to the outside of the reaction vessel during the heat treatment in the heat treatment step, it is possible to suppress the generation of by-products.

In addition, the acid gas is discharged so that the acid gas does not remain in the reaction vessel in the reaction step or the heat treatment step.

In the present invention, a film forming step of forming a carbon film by adding a carbon-based material in the heat treatment step may be further performed.

Furthermore, the present invention is a silicon oxide powder for a secondary battery negative electrode material that the oxygen content (x) of silicon oxide (SiOx) is 1 < x < 1.7, and the average particle size distribution of the powder meets the range of 0.1 to 1.0 μm ( SiOx) as an anode material, a reversible capacity of 1,700 to 1,900 mAh/g and a reversible ratio of 50 to 65% of performance is provided.

According to the method for producing silicon oxide powder according to the present invention, silicon chloride and polyhydric alcohol or water are wet-reacted, and exothermic reaction conditions such as the order and rate of adding the silicon chloride and polyhydric alcohol to the reaction vessel are precisely controlled. By doing so, it is possible to prepare a silicon oxide (SiOx) powder that satisfies physical properties suitable for a secondary battery negative electrode material use.

In addition, by performing the dispersion step of the silicon oxide in the gel state generated in the reaction step using ultrasonic stirring, the particle size is small, it has a uniform particle size distribution, and the pulverization process can be simplified.

Furthermore, the present invention provides a secondary battery using the oxide (SiOx) powder obtained from the above manufacturing method as a negative electrode material for secondary batteries.

1 is a view showing the state of the reaction product and the calcined material after calcination of the reaction product in the reaction step of the manufacturing method of the present invention, and FIG. 2 is a polyhydric alcohol after silicon chloride is added to the reaction vessel in the reaction step of the manufacturing method of the present invention. It shows the reversible capacity of the secondary battery according to the input rate,
3 is a view showing the secondary battery life according to the polyhydric alcohol input rate after silicon chloride is added to the reaction vessel in the reaction step of the manufacturing method of the present invention;
Figure 4 shows the reversible capacity of the secondary battery according to the reactant mixture ratio in the reaction step of the manufacturing method of the present invention,
5 shows the lifespan of the secondary battery according to the mixing ratio of the reactants in the reaction step of the manufacturing method of the present invention.

Hereinafter, the present invention will be described in detail.

In the present invention, the first reactant material, silicon chloride, and the second reactant, polyhydric alcohol or water, are wet-reacted in a reaction vessel. a reaction step for generating silicon oxide (SiOx) in a state; and

A heat treatment step for heat-treating the silicon oxide in the gel state to produce a silicon oxide powder,

In the reaction step, after the entire amount of the first reactant is put into the reaction vessel, the second reactant is added at an administration rate of less than 5 vol%/min and reacted while the second reactant is subsequently added. Provided is a method for producing a silicon oxide powder for an anode material.

In the method for producing silicon oxide powder of the present invention, the reaction step is a polyhydric alcohol or water (H ₂ ) as a second reaction material after adding silicon chloride as a first reaction material to a sealable reaction vessel provided with a stirrer therein. O) is added at a precisely controlled rate and these reactants are stirred and reacted in a closed state, for example, at a temperature of 50 to 300° C., for 2 to 72 hours, to prepare nanopowder having the desired physical properties. In addition, in the reaction step, ethanol is additionally supplied for reactivity control in the exothermic reaction process between the first reactant and the second reactant, or an unnecessary and undesired reaction is performed. In order to suppress, an inert gas such as N ₂ /Ar may be additionally supplied, and it may be performed while discharging an acid gas such as hydrochloric acid (HCl) gas generated during the reaction.

More specifically, in the present invention, in preparing silicon oxide powder by a wet liquid method through an exothermic reaction of a metal chloride as a first reactant and a polyhydric alcohol or water as a second reactant, the silicon chloride (SiCl ₄ ) ) and exothermic reaction conditions such as the order and rate of input of ethylene glycol can be precisely controlled to produce silicon oxide (SiOx) powder that satisfies physical properties suitable for secondary battery negative material use.

Silicon chloride, which is the first reaction material, uses at least one selected from the group consisting of silicon tetrachloride and dialkyldichlorosilane, and in an embodiment of the present invention, SiCl ₄ is used. will not be limited.

As the polyhydric alcohol as the second reaction material, the glycol component is at least one selected from the group consisting of ethylene glycol, propylene glycol and pinacol, and in the embodiment of the present invention, ethylene glycol (EG, Ethylene Glycol) is used. It will not be limited to this.

1 shows the calcined material state after calcination of the reaction product and the reaction product in the above reaction step.

1 (a) is a reaction product state when the polyhydric alcohol or water, which is a second reactant, is first added in the entire amount, and then silicon chloride, which is a first reactant, is subsequently added. It shows the state of the reaction product when the volumetric mixing ratio is 1:1.5 or more, or when the input rate of the subsequently added reactant is 5 vol%/min or more, FIG. 1(c) is shown in FIG. 1(b) It shows the state of the calcined material that has passed through the calcination step of the reaction product.

At this time, as shown in FIG. 1( a ), in the case where the polyhydric alcohol or water, which is the second reaction material, is first added in the entire amount in the reaction system, and then the metal chloride is subsequently added, the metal chloride and the metal chloride in the liquid layer of the polyhydric alcohol or water A rapid reaction of , a rapid temperature rise (60 to 100 ℃) in the lower part of the liquid layer may occur, and a large amount of acid gas may be discharged.

In addition, in this case, a sponge-like metal oxide is generated on the upper portion of the liquid layer, and unreacted polyhydric alcohol or water remains in the lower portion of the liquid layer. As it decomposes, a large amount of the polyhydric alcohol or water at the bottom is absorbed and gelation may occur. On the other hand, the non-reacted polyhydric alcohol or water at the lower part is filtered and the sponge-like metal oxide on the upper part is calcined to be described later during the heat treatment step. When calcined in , a white metal oxide is produced, which cannot be used as an anode material for a secondary battery. Therefore, in the method for producing a silicon oxide powder of the present invention, in the reaction step, the reactant is added to the silicon as the first reactant material. The above problem can be solved by adding polyhydric alcohol or water, which is the second reactant material, after the entire amount of chloride is added to the reaction vessel. Alternatively, even when water is subsequently added, the physical properties of the product generated by the reaction and the physical properties of the nanopowder prepared therefrom may be different depending on the mixing ratio of the reactants and the input rate of the subsequently added reactants. Specifically, , The volume mixing ratio of silicon chloride as the first reactant as the reactant and polyhydric alcohol or water as the second reactant as the reactant is less than 1:1.5, for example, 1:0.2 to 1:1 , preferably 1:0.5 to 1 :1.0, more preferably 1:0.3 to 1:0.6, and the rate of addition of polyhydric alcohol or water subsequently added in the reaction material is less than 5 vol%/min, preferably 2 vol%/min compared to silicon chloride min or less, for example, 0.5 vol%/min to 2 vol%/min, more preferably 0.5 vol%/min to 1 vol%/min. In this case, the volumetric mixing ratio of the reactant is 1 : 1.5 or more, or the rate of addition of the subsequently added reactant is 5 vol%/mi When n or more, as shown in Fig. 1(b), the reaction product in the reaction vessel is in the form of a gel, so that unreacted polyhydric alcohol or water in excess remains around the product, as shown in Fig. 1(c) , the calcined product produced by calcining the reaction product or nanoparticles produced through it are blackish-brown, and in particular, in the case of silicon oxide (SiOx), the x value exceeds 1.7 and exceeds 1.8 and the particle size increases, and the particle size increases, and the coin is a lithium ion battery. When applied to a cell, the reversible capacity is 900 to 1,100 mAh/g, and the reversible ratio is insufficient at the level of 50%.

On the other hand, when the volumetric mixing ratio of the reactants is 1:0.5 to 1:1.0 and the rate of input of the subsequently added reactants is 1 to 2 vol%/min, the reaction products in the reaction vessel are shown in FIG. 1(d) As shown, it is formed in the form of white sugar powder and only a small amount of unreacted polyhydric alcohol or water remains around the product, and as shown in FIG. The produced nanoparticles have a black color, and in particular, in the case of silicon oxide (SiOx), the x value may be formed as fine particles satisfying the range of 1.4 to 1.7, and when applied to a coin cell, which is a lithium ion battery, the reversible capacity is 1,700 to 1,900 Sufficient performance can be secured at mAh/g and a reversible ratio of 65%. From the above, the method for producing silicon oxide powder of the present invention is a wet method of silicon chloride (SiCl ₄ ) and polyhydric alcohol ethylene glycol (EG, Ethylene Glycol). However, by precisely controlling the exothermic reaction conditions such as the order and rate of adding the silicon chloride (SiCl ₄ ) and ethylene glycol to the reaction vessel, silicon oxide (SiOx) that meets physical properties suitable for secondary battery negative material use ) powder can be produced. In addition, in the method for producing silicon oxide powder of the present invention, after the reaction step, a dispersing step using ultrasonic stirring of the generated silicon oxide in a gel state may be further performed.

The dispersion step using ultrasonic agitation generates waves in the solution due to the physical agitation of ultrasonic waves and thereby promotes dispersion, thereby shortening the progress rate and, in particular, increasing the uniformity of the gel due to intermolecular dispersion of silicon oxide in the gel state and reacting It is possible to reduce the particle size of the product. Therefore, it is possible to simplify the process of pulverizing the product after the calcination step by controlling the uniform particle size during dispersion.

In the method for producing silicon oxide powder of the present invention, it is preferable that an inert gas is supplied into the reaction vessel in the reaction step, and in the heat treatment step, after waiting in the first atmospheric step in an atmosphere of 100±20° C. conduction, 400 In the preheating step of ±20°C atmosphere, it may be preheated for a predetermined time and then transferred to the calcination step performed at 600 to 900°C.

The first standby step is performed to prevent heat generated in the preheating step and the firing step from being transferred to the outside and to minimize heat loss. It may be performed to remove 90% or more of gases such as.

In the firing step, when the heat treatment temperature is less than 600 ° C, crystallization does not occur, so when the nano powder is used as an anode material for a secondary battery, it is not easy to react with lithium, and when it exceeds 900 ° C, it is carbonized in the gel Due to this, wet nanopowder crystal growth may not occur. In the heat treatment step, by supplying an inert gas to the outside of the reaction vessel while the heat treatment is performed, the generation of by-products may be suppressed.

At this time, if the supply of an inert gas such as N ₂ /Ar inside the kiln is insufficient, the product reacts with O ₂ in the atmosphere to generate SiO ₂ in the reaction vessel. Therefore, it is necessary to supply an inert gas as described above. By performing the dispersion step by ultrasonic stirring in the manufacturing method of the present invention, it is easy to control the uniform particle size during dispersion, thereby simplifying the process of pulverizing the product after the firing step there is.

In addition, by allowing the acid gas to be discharged in the reaction step or the heat treatment step, the acid gas does not remain in the reaction vessel.

In the present invention, a film forming step of forming a carbon film by adding a carbon-based material in the heat treatment step may be further performed.

Due to the carbon film forming step, by forming a carbon film on silicon oxide, it is possible to prevent volume expansion by the carbon film during charging/discharging.

In the above, carbon may be at least one selected from the group consisting of carbon nanofibers, graphene oxide, reduced graphene oxide and graphene, and the carbon film formation method is a method of reacting the carbon precursor with silicon oxide in a gas phase Including, other known methods may be adopted and applied.

Furthermore, the present invention is a silicon oxide powder for a secondary battery negative electrode material that the oxygen content (x) of silicon oxide (SiOx) is 1 < x < 1.7, and the average particle size distribution of the powder meets the range of 0.1 to 1.0 μm ( To provide a secondary battery using SiOx) as an anode material.

At this time, the secondary battery using the silicon oxide powder (SiOx) for the secondary battery negative electrode material as the negative electrode material has a reversible capacity of 1,700 to 1,900 mAh/g and a reversible ratio of 50 to 65% of performance.

When the oxygen content (x) of the silicon oxide (SiOx) is close to 1 on average, stable battery characteristics, high cycle characteristics, and manufacturing cost can be lowered, and the capacity efficiency of the secondary battery and volume expansion during charging/discharging and While making it possible to achieve a gentle contraction, it is possible to efficiently maintain a high capacity.

Therefore, preferably, the oxygen content (x) of the silicon oxide (SiOx) is 1 < x < 1.7 fine particles, in this case, if less than 1 in the above, the actual compatibility falls due to manufacturing difficulty and if it exceeds 1.7, lithium The charge/discharge capacity of the ion secondary battery is reduced.

Silicon oxide powder (SiOx) for secondary battery negative electrode material of the present invention is a silicon oxide (SiOx) in the manufacturing process of silicon chloride (SiCl ₄ ) and polyhydric alcohol ethylene glycol (EG, Ethylene Glycol) by wet reaction of the silicon gel However, by precisely controlling the conditions of the order, the input rate, and the reaction material mixing ratio of the silicon chloride (SiCl ₄ ) and ethylene glycol to the reaction vessel, it is possible to meet the physical properties suitable for the secondary battery negative material use. there is.

In addition, by ultrasonically stirring the silicon oxide in the gel state, it is possible to increase the uniformity of the gel and reduce the particle size of the reaction product due to the intermolecular dispersion of the silicon oxide in the gel state.

2 and 3 show the reversible capacity and lifespan of the secondary battery according to the polyhydric alcohol input rate after silicon chloride is added to the reaction vessel in the reaction step of the manufacturing method of the present invention, and FIGS. 2 and 3 After STC (SiCl ₄ ) was put into a reaction vessel made of silver titanium (Ti) or quartz, ethylene glycol (EG) was reacted in the reaction step at the input rate described in Table 1 below. A secondary battery was manufactured by manufacturing and applying it as a negative electrode material of a secondary battery, and the measurement results of the capacity (capacity) of each secondary battery and the reversible capacity (specific capacity) according to the number of charge cycles are shown. As a result, in the case of condition-B and condition-C in which the input rate of the polyhydric alcohol is less than 5 vol%/min, the capacity of the secondary battery increases and lifespan extension can be confirmed.

In addition, FIGS. 4 and 5 show the reversible capacity and lifespan of the secondary battery according to the reactant mixture ratio in the reaction step of the manufacturing method of the present invention, and FIGS. 4 and 5 show titanium (Ti) or After STC (SiCl ₄ ) was introduced into a reaction vessel made of quartz, ethylene glycol (EG) was added at an input rate of 1.0 vol%/min at the volume mixing ratio shown in Table 2 to generate a reaction product, and then heat treatment to prepare nanopowder Thus, a secondary battery was manufactured by applying this as an anode material of a secondary battery, and the measurement result of measuring the capacity (capacity) of each secondary battery and the reversible capacity (specific capacity) according to the number of charge cycles is shown. As a result, in the case of Condition-A to Condition-C in which the volumetric mixing ratio of the reactant (SiCl ₄ :EG) is less than 1:1.5, the capacity of the secondary battery increased and the lifespan was extended, and in particular, the volumetric mixing ratio of the reactant was 1: In the case of condition-B of 0.5, the capacity of the secondary battery is the largest and it can be confirmed that the lifespan is extended.

Hereinafter, the present invention will be described in more detail through examples.

These examples are for explaining the present invention in more detail, and the scope of the present invention is not limited to these examples.

<Examples 1-2>

After silicon chloride (SiCl ₄ ) is added to a reaction vessel made of titanium (Ti), ethylene glycol (EG) is added at the input rate shown in Table 1 below to generate a reaction product, and then a nanopowder is prepared through heat treatment, which is a secondary A secondary battery was manufactured by applying it as an anode material of the battery, and the reversible capacity (specific capacity) according to the capacity and number of charge cycles of each secondary battery was measured, and the measurement results are shown in the graphs of FIGS. 2 and 3 . As shown.

As shown in FIGS. 2 and 3, in the case of condition-A in which the polyhydric alcohol input rate is 5 vol%/min, the capacity of the secondary battery is insufficient and the reversible capacity almost disappears when the number of charge cycles is around 50, so the life of the battery It has been confirmed that this is done.

On the other hand, in the case of condition-B and condition-C, in which the input rate of polyhydric alcohol was less than 5 vol%/min, the capacity of the secondary battery increased and the lifespan was extended, especially in condition-B where the input rate was 1.0 vol%/min or less. In this case, it was confirmed that the secondary battery had the largest capacity and the longest lifespan.

<Examples 3-5>

After silicon chloride (SiCl ₄ ) was added to the reaction vessel made of quartz, ethylene glycol (EG) was added at 1.0 vol%/min (Condition-B) to generate a reaction product, and then the ultrasonic stirring rate as shown in Table 2 below After controlling and dispersing, nanopowder was prepared through heat treatment.

As can be seen in Table 2, when the reaction product generated in the reaction step is dispersed using ultrasonic stirring, the particle size is reduced, and the product after the calcination step is adjusted by adjusting the uniform particle size during dispersion according to the ultrasonic control. The grinding process can be simplified.

<Examples 6-8>

After adding silicon chloride (SiCl ₄ ) as a reaction material to a reaction vessel made of titanium (Ti), ethylene glycol (EG) was added at an input rate of 1 vol%/min at the volumetric mixing ratio shown in Table 3 below to prepare the reaction product After production, nanopowder is prepared through heat treatment and the secondary

A secondary battery was prepared by applying it as a negative electrode material of the battery.

As shown in FIGS. 4 and 5 , in the case of Condition-D where the volumetric mixing ratio of the reactants is 1:1.5 or more, the capacity of the secondary battery is insufficient and the reversible capacity is almost gone when the number of charging cycles is around 50, so that the life of the battery is exhausted. confirmed to be

On the other hand, in the case of Condition-A to Condition-C in which the volume mixing ratio of the reactants is less than 1:1.5, the capacity of the secondary battery increased and the lifespan was extended, especially in the case of Condition-B where the volume mixing ratio of the reactants was 1:0.5 It was confirmed that the secondary battery had the largest capacity and the longest lifespan.

In the above, the present invention has been described in detail only with respect to the described embodiments, but it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical spirit of the present invention, and it is natural that such modifications and modifications belong to the appended claims.

Claims (10)

In a reaction vessel, a silicon chloride as a first reactant material and a polyhydric alcohol or water as a second reactant material are wet-reacted, and the volumetric mixing ratio of the first reactant material and the second reactant material is less than 1:1.5, and the silicone gel a reaction step to produce an oxide (SiOx); and
A heat treatment step for heat-treating the silicon oxide in the gel state to produce a silicon oxide powder,
In the reaction step, after injecting the entire amount of the first reactant into the reaction vessel, the second reactant is added and reacted at an administration rate of less than 0.5 to 5 vol%/min while the second reactant is subsequently added;
After the reaction step, the method for producing a silicon oxide powder for a secondary battery negative electrode material, characterized in that further performing the dispersing step using ultrasonic stirring for the generated silicon oxide in the gel state. delete The method of claim 1, wherein in the reaction step, a volume mixing ratio of the first reactant and the second reactant is 1:0.5 to 1:1.0. delete The method of claim 1, wherein in the reaction step, an inert gas is supplied into the reaction vessel. According to claim 1, wherein the heat treatment step is a first standby step maintained at 100 ± 20 °C, a preheating step maintained at 400 ± 20 °C, a calcination step performed at 600 to 900 °C, a second standby step and a cooling step A method for producing a silicon oxide powder for a secondary battery negative electrode material, characterized in that it comprises. The method of claim 1, wherein in the heat treatment step, an inert gas is supplied to the outside of the reaction vessel during the heat treatment to suppress the generation of by-products. The method of claim 1, wherein the acid gas is discharged so that the acid gas does not remain in the reaction vessel in the reaction step or the heat treatment step. The method of claim 1, wherein the film forming step of forming a carbon film by adding a carbon-based material in the heat treatment step is further performed. The oxygen content (x) of silicon oxide (SiOx) is 1 < x < 1.7 fine particles,
A silicon oxide powder (SiOx) for a secondary battery negative electrode material prepared by the method of any one of claims 1, 3, 5 to 9, wherein the average particle size distribution of the powder satisfies the range of 0.1 to 1.0 μm A secondary battery used as an anode material.

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